Method and network device for multi-path communication

ABSTRACT

A method for transmitting data packets of at least one communication service from a first network entity to at least one destination network entity includes: establishing a quick user datagram protocol internet connection tunnel between the first network entity and a second network entity; transmitting the data packets from the first network entity to the second network entity via the quick user datagram protocol internet connection tunnel, wherein the data packets are encapsulated within quick user datagram protocol internet connection packets, and wherein the quick user datagram protocol internet connection packets are transmitted from the first network entity to the second network entity via multiple paths; extracting the data packets from the received quick user datagram protocol internet connection packets in the second network entity; and forwarding the extracted data packets from the second network entity to a respective destination network entity.

CROSS-REFERENCE TO PRIOR APPLICATIONS

This application is a U.S. National Phase application under 35 U.S.C. §371 of International Application No. PCT/EP2020/080829, filed on Nov. 3,2020, and claims benefit to European Patent Application No. EP19207381.5, filed on Nov. 6, 2019. The International Application waspublished in English on May 14, 2021 as WO 2021/089552 A1 under PCTArticle 21(2).

TECHNICAL FIELD

The invention relates to a method for transmitting data packets of atleast one communication service from a first network entity to at leastone destination network entity via multiple paths.

BACKGROUND

A Hybrid Access Network is a special architecture for broadband accessnetworks where two different network technologies are combined, forinstance combining one xDSL network with a wireless network such as LTE.Similarly, 3GPP ATSSS (3rd Generation Partnership Project Access TrafficSteering, Switching and Splitting) refers to an architecture in which3GPP and non-3GPP accesses are combined. Access Traffic Steering refersto a procedure that selects an access network for a new data flow andtransfers the traffic of this data flow over the selected accessnetwork, Access Traffic Switching refers to a procedure that moves alltraffic of an ongoing data flow from one access network to anotheraccess network in a way that maintains the continuity of the data flow,and Access Traffic Splitting refers to a procedure that splits thetraffic of a data flow across multiple access networks, wherein whentraffic splitting is applied to a data flow, some traffic of the dataflow is transferred via one access and some other traffic of the samedata flow is transferred via another access. Access Traffic Steering,Switching and Splitting is applicable between 3GPP and non-3GPPaccesses. Devices which are connectable to more than one network arealso referred to as multi-homed devices.

For the purpose of simultaneously using multiple paths between peers,there exist several multipath network protocols like MPTCP (MultipathTransmission Control Protocol) standardized by IETF in RFC 6824, January2013, CMT-SCTP described by P. Amer et al. in the document “Load Sharingfor the Stream Control Transmission Protocol (SCTP),draft-tuexen-tsvwg-sctp-multipath-18, Jul. 22, 2019” and MP-DCCP asdisclosed in the document “DCCP Extensions for Multipath Operation withMultiple Addresses, draft-amend-tsvwg-multipath-dccp-02” by M. Amend etal., Jul. 8, 2019.

In order to overcome TCP and HTTP limitations, the so-called QUICprotocol, its name “QUIC” originally proposed as the acronym for “QuickUDP Internet Connections”, was initiated in 2013. An earlier effort inthat context was the so-called SPDY. The decision not to evolve TCPitself was made because of backwards compatibility reasons and the slowpenetrations and deployments of such evolvements. QUIC is running overUDP and promises performance benefits over TCP, even though it imitatesa lot of its characteristics like congestion control and reliablein-order delivery. However, it extends the scope over TCP when includingstream multiplexing and end-to-end encryption. In 2018 the decision wasmade that the next HTTP version HTTP/3 will run over QUIC. QUIC needs,like other transport protocols also, explicit implementation andselection by services.

The QUIC protocol thus is a general-purpose transport layer networkprotocol, which presently is in the process of standardization withinthe IETF. The current status of the standardization by the IETF WorkingGroup is described in the Internet draft “QUIC: A UDP-Based Multiplexedand Secure Transport, draft-ietf-quic-transport-23” by J. Iyengar etal., Sep. 12, 2019. In the following, the content of said Internet draftis also referred to as the current QUIC design. Non-standardizedversions of QUIC are already in use and are for instance implemented incertain web browsers.

SUMMARY

In an exemplary embodiment, the present invention provides a method fortransmitting data packets of at least one communication service from afirst network entity to at least one destination network entity. Themethod includes: establishing a quick user datagram protocol internetconnection tunnel between the first network entity and a second networkentity; transmitting the data packets from the first network entity tothe second network entity via the quick user datagram protocol internetconnection tunnel, wherein the data packets are encapsulated withinquick user datagram protocol internet connection packets, and whereinthe quick user datagram protocol internet connection packets aretransmitted from the first network entity to the second network entityvia multiple paths; extracting the data packets from the received quickuser datagram protocol internet connection packets in the second networkentity; and forwarding the extracted data packets from the secondnetwork entity to a respective destination network entity.

BRIEF DESCRIPTION OF THE FIGURES

Subject matter of the present disclosure will be described in evengreater detail below based on the exemplary figures. All featuresdescribed and/or illustrated herein can be used alone or combined indifferent combinations. The features and advantages of variousembodiments will become apparent by reading the following detaileddescription with reference to the attached drawings, which illustratethe following:

FIG. 1 depicts a schematic view of a non-working communication systemillustrating a problem which is solved by the invention;

FIG. 2 depicts a schematic view of a communication system according toan embodiment of the invention; and

FIG. 3 depicts a schematic view of a reference topology for HybridAccess.

DETAILED DESCRIPTION

Exemplary embodiments of the present invention provide a way for datapackets of at least one communication service to be transmitted from afirst network entity to at least one destination network entity viamultiple paths using a QUIC protocol.

In the context of the present invention, the term QUIC shall encompass,unless otherwise stated, a protocol having the features according to thecurrent status of standardization of the QUIC protocol by the IETF or aprotocol according to a future standard of the QUIC protocol. Since theinvention provides certain extensions and/or amendments of the QUICprotocol, however, in the context of the present invention the term QUICshall not be limited to the current status of standardization of theQUIC protocol by the IETF, but shall also encompass these extensionsand/or amendments, in particular with regard to the establishing of atunnel and the employment of MP-QUIC and in certain embodiments alsowith regard to the utilization of non-reliable data transmission.

According to an embodiment of the present invention, between a firstnetwork entity and a second network entity a QUIC tunnel is establishedand for the data transmission between the first and second networkentity a Multi-Path QUIC (MP-QUIC) protocol is used. A preferred aspectof the invention further lies in the utilization of non-reliable datatransmission between the first network entity and the second networkentity.

In FIG. 1 a non-working system architecture is shown for illustrating aproblem which is encountered when the QUIC protocol shall be utilizedvia multiple paths, for instance in a hybrid access network or in thecontext of 3GPP ATSSS. In the theoretical, non-working communicationsystem 10′ shown in FIG. 1 a user equipment 100′ is simultaneouslyconnected to a converter server 200′ via an LTE network 310 and an xDSLnetwork 320. The user equipment 100′ could be a hybrid customer premisesequipment router and the converter 200′ could be a hybrid aggregationgateway in a server of a communication provider.

Since QUIC and TCP share a lot of similarities regarding their transportcharacteristics, the experience with the MP-TCP protocol could be usedand transferred to a MP-QUIC protocol. An MP-QUIC protocol which iscomparable to MP-TCP can split QUIC connections over multiple paths andrelies on QUIC's reliable in-order delivery.

In the system 10′ applications 110′, 120′, 130′ and 140′ indicating anumber of n applications running on the user equipment 100′ shall usesuch MP-QUIC protocol for transmitting data packets via multiple paths,i.e. via networks 310 and 320, to the converter 200′. The converter 200′shall then forward the received data packets via the Internet 400 torespective destination applications 510′, 520′, 530′ and 540′ indicatinga number of n destination applications, which use the QUIC protocol andwhich might be running on various devices or servers.

However, an MP-QUIC protocol which is comparable to MP-TCP can only workend-to-end and does not tolerate an interception, because of itsinherent end-to-end encryption. Therefore, a proxy 250′ which would beneeded to translate the MP-QUIC protocol into the QUIC protocol cannotbe realized and accordingly the communication system 10′ as shown inFIG. 1 is a non-working system illustrating a general problem which isencountered when trying to utilized the QUIC protocol via multiplepaths. As a result, inclusion into Hybrid Access or 3GPP ATSSS foroperator controlled traffic management does not work on a QUIC orMP-QUIC protocol level.

In FIG. 2 a schematic view of a preferred embodiment of a communicationsystem 10 according to the invention is shown, in which the abovedescribed problem is solved.

The communication system 10 comprises user equipment 100, wherein in anumber of n applications communication services are running whichrespectively generate data packets which are to be transmitted to arespective destination network entity. The data packets are generated onthe basis of a communication protocol which is selected depending on therespective communication service. In the embodiment shown in FIG. 2 , afirst application 110 is generating QUIC data packets, a secondapplication 120 is generating UDP data packets, a third application 130is generating IP data packets, and an nth application 140 is generatingTCP data packets. In the shown embodiment, the different data packetsfrom the different application are routed to a virtual network interfaceVNIF 150 which may be implemented in a hybrid customer premisesequipment router. The applications 110, 120, 130 and 140 may be runningon said router or on any kind of terminal device which is connected tothe router, wherein such terminal device may be a mobile phone, apersonal computer, a tablet PC, a smart TV set, or the like.

In the shown embodiment the virtual network interface 150 is connectedto a virtual network interface 250 in a converter 200, wherein saidconverter 200 preferably is a hybrid aggregation gateway in a server ofa communication provider. The hybrid user equipment 100 and the hybridconverter 200 are simultaneously connected via at least two differentnetworks, thus enabling data transmission via multiple paths. In theshown embodiment, the virtual network interface 150 is connected tovirtual network interface 250 via an LTE network 310 and via a xDSLnetwork 320. Other types of networks may also be utilized, wherein insuch a case the user equipment 100 and the converter 200 are thenprovided with respective network interfaces adapted for communicationvia said other types of networks.

In an exemplary embodiment, a QUIC tunnel is established between a firstnetwork entity and a second network entity, wherein in the embodimentshown in FIG. 2 the first network entity is the user equipment 100 andthe second network entity is the converter 200, and the QUIC tunnel isestablished between the virtual network interface 150 and the virtualnetwork interface 250. Establishing a QUIC tunnel means to establish aconnection using a tunneling protocol on the basis of the QUIC protocol.

TCP is often used as a tunneling protocol. QUIC can similarly be used asa tunneling protocol, allowing tunneling services to maintain thebenefits of QUIC, without degrading the performance and securitycharacteristics.

A tunneling protocol is a communications protocol that allows for thetransmission of data from one network entity to another network entitythrough a process called encapsulation. Because the QUIC tunnelinginvolves repackaging the traffic data into a different form, withencryption as standard, due to the use of the QUIC protocol, it can hidethe nature of the traffic that is run through a tunnel. A tunnelingprotocol works by using the data portion of a packet, i.e. the payload,to carry the packets that actually provide the service. Tunneling uses alayered protocol model such as those of the OSI or TCP/IP protocolsuite, but usually violates the layering when using the payload to carrya service not normally provided by the network. Typically, the deliveryprotocol operates at an equal or higher level in the layered model thanthe payload protocol.

A QUIC tunnel between two multi-path capable entities, such as entities100 and 200, can typically transport any network traffic from Layer 2upwards. In the embodiment shown in FIG. 2 the data packets which areencapsulated into QUIC packets exemplary comprise QUIC data packets fromapplication 110, UDP data packets from application 120, IP data packetsfrom application 130 and TCP data packets from application 140.

In an exemplary embodiment, both QUIC tunnel termination points, in theembodiment shown in FIG. 2 virtual network interfaces 150 and 250,employ an MP-QUIC protocol, so that the QUIC tunnel itself isdistributed over the multiple paths.

The current design of QUIC does not enable multi-homed or hybrid accessdevices to efficiently use different paths simultaneously. Therefore, inorder to utilize an MP-QUIC protocol within the QUIC tunnel, anexemplary embodiment provides a respective extension of the current QUICprotocol.

Typically a path is defined by a 4-tuple, comprising Source IP Address,Source Port Number, Destination IP Address, and Destination Port Number.QUIC paths are host-specific, i.e., the path from A to B is differentfrom the one from B to A, which enables the use of unidirectionalnetworks such as satellites, unapplicable when using TCP.

Furthermore, QUIC is not bound to a particular 4-tuple during thelifetime of a connection. A QUIC connection is identified by aConnection ID, placed in the public header of each QUIC packet. Thisenables hosts to continue the connection even if the 4-tuple changes.This ability to shift a connection from one 4-tuple to another is calledConnection Migration. A QUIC peer can thus start on a given path,denoted as the initial path, and end on another one. However, thecurrent QUIC design assumes that only one symmetric path is in use for agiven connection.

In the following, a possible establishment of a Multipath QUICconnection between a first network entity and a second network entity isexemplary described. A Multipath QUIC connection may start like aregular QUIC connection, wherein a handshake takes place according tothe current QUIC design. During this handshake a multipath capabilitymay be negotiated between the network entities, in the embodiment asshown in FIG. 2 between the user equipment 100 and the converter 200utilizing virtual network interfaces 150 and 250. For this purpose, arespective parameter is transmitted between the network entities whichindicates the capability of the respective network entity for multi-pathtransmission. The parameter may for instance indicate the number ofpaths which may be simultaneously supported by the respective networkentity. In an embodiment, no transmitted parameter or a parameter with avalue of zero indicates no support for multi-path transmission and anyother parameter value indicates support for multi-path transmission.

An established Multipath QUIC connection comprises at least two paths,wherein each path is associated with a different four-tuple and isidentified by a Path ID, wherein the respective Path IDs are negotiatedbetween the network entities. As an extension over the current QUICdesign the Path ID is transmitted in all or at least in certain QUICpackets, wherein the Path ID may be placed in the public header of therespective QUIC packets.

Thus, the invention provides for the combination of a QUIC tunnel andthe use of a MP-QUIC protocol for data transmission between a first anda second network entity, wherein the first network entity in particularis a user device, such as a hybrid access router or a smartphone havingtwo network interfaces for connecting to respectively differentnetworks, and wherein the second network entity in particular is aserver in the core network of a communication provider, such as a hybridaggregation gateway.

Again referring to FIG. 2 , a service using the IP compatible multipathframework as described above, based on QUIC encapsulation in the QUICtunnel, sends its payload through the virtual network interface 150. Theshown exemplary services provided by applications 110, 120, 130 and 140generate different types of data packets, e.g. IP packet, UDP datagrams,QUIC segments, TCP segments or Ethernet frames. Each of the virtualnetwork interfaces 150 and 250 acts as the entry or exit point of the IPcompatible multipath framework, depending on the direction of traffictransmission. After entering the respective one of virtual networkinterfaces 150 or 250, the payload becomes encapsulated into the QUICtunnel. In a next step, MP-QUIC takes over transmission control anddecides on which path out of a potential bunch of path, the encapsulatedpayload is sent. On the receiver side, the packets are received by theMP-QUIC stack. When they become released and the MP-QUIC are strippedoff, i.e. the encapsulation is removed, the piggybacked payload exitsthe respective virtual network interface on receiver side ready to beforwarded to the respective one of the original service endpoints 510,520, 530 or 540 via the Internet 400.

As described above, within the QUIC tunnel various types of data packetsmay be encapsulated and transmitted as payload, wherein certain types ofdata packets may be transmitted between the communication endpointsusing a reliable transmission, as for instance TCP data packetstransmitted between applications 140 and 540.

The Transmission Control Protocol, or short TCP, aims to provide aninterface for sending streams of data reliably between two endpoints,wherein data is handed to the TCP system, which ensures the data makesit to the other end in exactly the same form, or the connection willindicate that an error condition exists. To do this, TCP breaks up thedata into network packets and adds small amounts of data to each packet.This additional data includes a sequence number that is used to detectpackets that are lost or transmitted out of order, and a checksum thatallows the errors within packet data to be detected. When either problemoccurs, TCP uses automatic repeat request (ARQ) to tell the sender tore-send the lost or damaged packet. In most implementations, TCP willsee any error on a connection as a blocking operation, stopping furthertransfers until the error is resolved or the connection is consideredfailed. If a single connection is being used to send multiple streams ofdata, as is the case in the HTTP/2 protocol, all of these streams areblocked although only one of them might have a problem. This phenomenonis called head-of-line blocking.

QUIC aims to be nearly equivalent to a TCP connection but with reducedlatency. QUIC uses UDP as its basis, which does not include lossrecovery. Instead, each QUIC stream is separately flow controlled andlost data retransmitted at the level of QUIC, not UDP. This means thatif an error occurs in one stream, the protocol stack can continueservicing other streams independently. However, head-of-line blockingstill occurs with respect to the one stream which has the error.

To ensure no head-of-line blocking by the QUIC tunnel, in case ofdisturbance, a mechanism is preferably applied within QUIC which relaxesits reliable transmission.

Furthermore, if data packets of a protocol such as TCP, which employsreliable transmission and accordingly performs re-transmissions in caseof error and reordering of data packets, are encapsulated within theQUIC tunnel, a conflict may arise, when also within the QUIC tunnel areliable transmission would be performed with re-transmissions andreordering of piggybacked TCP packets and underlying QUIC packetssimultaneously. Such a conflict might lead to significant increase oflatency and/or decrease of throughput.

Therefore, in a preferred embodiment of the invention, quick userdatagram protocol internet connection packets or QUIC packets aretransmitted non-reliably between the first and the second networkentities 100 and 200. For this purpose, preferably an information istransmitted from the first network entity to the second network entityindicating non-reliable transmission within the QUIC tunnel, whereinthis information may be transmitted in a handshake according to thecurrent QUIC design. In response, the quick user datagram protocolinternet connection packets or QUIC packets are transmittednon-reliably, i.e. without re-transmissions in case of packet loss andwithout re-ordering.

A non-reliable data transmission, preferably for the data transmissionwithin the QUIC tunnel, is another extension of the current QUIC design.For this purpose, preferably a different or an additional frame type maybe defined and indicated by a parameter within a QUIC packet.

Greatly differing transmission characteristics of the multiple paths mayhowever lead an amount of scrambling of the encapsulated data packetswhich might result in problems for communication services which utilizereliable transmission, for instance reliable transmission of TCP datapackets. Therefore, in a preferred embodiment, forwarding the extracteddata packets from the second network entity, for instance converter 200to the respective destination network entity, for instance networkentity 510, 520, 530 or 540, is performed in an order depending onordering information, which is comprised in the encapsulated datapackets, such as a TCP data packet, and/or in the quick user datagramprotocol internet connection packets or QUIC packets.

In other words, a certain reordering is preferably performed, whichhowever typically is not a complete reordering, wherein in particularpacket loss is tolerated and accordingly no re-transmissions areperformed.

In a preferred embodiment, received data packets are queued in a reorderqueue in the second network entity for forwarding, wherein the datapackets in the reorder queue are reordered according to a pre-definedreorder criterion, and wherein data packets which are lost in thetransmission from the first network entity to the second network entityvia the tunnel are skipped in the reordering. Furthermore, mechanismsmay the used for the reordering as described in EP 3 531 637 A1.

The congestion control scheme as defined by the current QUIC design isnot suitable for data transmission via multiple paths. Therefore thiscongestion control scheme preferably is not used.

For MP-QUIC data transmission within the QUIC tunnel, the LIA congestioncontrol scheme as specified in RFC 6356 may be utilized, which is alsoused by Multipath TCP.

In a preferred embodiment, congestion control information may beextracted from the data packets transmitted as payload within the QUICtunnel in the first and/or in the second network entity, wherein inparticular said extracted congestion control information is used foradapting a congestion control of the QUIC tunnel between the firstnetwork entity and a second network entity.

In a further preferred embodiment of the invention, a maximumtransmission unit of at least one transmission path available fortransmitting data from the first network entity to the second networkentity is determined and the data size of the quick user datagramprotocol internet connection packets is selected depending on thedetermined maximum transmission unit.

The invention preferably combines three technologies for shaping an IPcompatible multipath framework as depicted in FIG. 2 , capable oftransporting IP packets, UDP datagrams and QUIC segments over multiplepaths, wherein said technologies are

-   QUIC encapsulation using a QUIC tunnel,-   employment of Multipath QUIC within the QUIC tunnel, and-   non-reliable transmission of the payload within the QUIC tunnel.

All of these technologies are extensions and/or modifications of thecurrent QUIC design.

As described above, an additional feature to guarantee efficientprocessing of the piggybacked payload through the QUIC tunnel might be are-assembly unit on receiver side to bring the payload in the same oralmost identical order as they were originated. The re-assembly unit canbe placed within QUIC or MP-QUIC but also as an external entity as longas some ordering information is available.

As an additional feature, a Path Maximum Transfer Unit (PMTU) probingmight be employed, when a new path joins the MP-QUIC session, to ensureno mismatch with the virtual network interface Maximum Transfer Unit(VNIF MTU) and to avoid fragmentation. In case the PMTU is lower thanthe difference of VNIF MTU and the encapsulation overhead, the VNIF MTUpreferably is adapted.

As another additional feature to avoid performance degradation by theQUIC tunnel some interaction with a potential inner congestion controlof the piggybacked payload may be employed, as described above, whereincongestion control parameters of the piggybacked payload may only bemeasured for monitoring purposes without performing congestion controlof the QUIC tunnel on that basis.

FIG. 3 shows a reference topology 600 for Hybrid Access (HA). Thereference topology 600 illustrates the Home Network zone 610 withCustomer Network 611 and Home Gateway with Hybrid Access Client 612, theIntegrated Operator Network 620 with a variety of operator networks 621,622, 623, 624, 625, 626 and the Internet zone 630 with the Internet 631.At the operator networks 621, 622, 623, 624, 625, 626, Hybrid Accessalgorithms and protocols 627 are implemented to connect the HybridAccess Client 612 with the Hybrid Access Server 628 for connection withthe Internet 631. The reference topology 600 as shown in FIG. 3 is anexample of a system in which the invention may be employed, wherein inFIG. 3 the first network entity as described above is the Hybrid AccessClient 612 and the second network entity is the Hybrid Access Server628.

At least some of the preferred aspects are summarized below. In thefollowing, the term “user datagram protocol internet connection packet”refers to a QUIC packet as described above, the format of which is basedon the current QUIC design extended and/or modified by the respectiveextensions and/or modifications provided by the invention as describedherein.

According to one aspect, a method for transmitting data packets of atleast one communication service from a first network entity to at leastone destination network entity is provided, comprising the steps ofestablishing a quick user datagram protocol internet connection tunnelbetween the first network entity and a second network entity,transmitting the data packets from the first network entity to thesecond network entity via said tunnel, wherein the data packets areencapsulated within quick user datagram protocol internet connectionpackets, and wherein the quick user datagram protocol internetconnection packets are transmitted from the first network entity to thesecond network entity via multiple paths, extracting the data packetsfrom the received quick user datagram protocol internet connectionpackets in the second network entity, and forwarding the extracted datapackets from the second network entity to the respective destinationnetwork entity.

In a preferred embodiment of the method, an information is transmittedfrom the first network entity to the second network entity indicatingnon-reliable transmission within the quick user datagram protocolinternet connection tunnel, wherein in response the quick user datagramprotocol internet connection packets are transmitted non-reliably.

Preferably, the data packets and/or the quick user datagram protocolinternet connection packets comprise ordering information, whereinforwarding the extracted data packets from the second network entity tothe respective destination network entity is performed in an orderdepending on said ordering information.

Preferably, for forwarding the received data packets are queued in areorder queue in the second network entity, and wherein the data packetsin the reorder queue are reordered according to a pre-defined reordercriterion, and wherein data packets which are lost in the transmissionfrom the first network entity to the second network entity via thetunnel are skipped in the reordering.

The quick user datagram protocol internet connection tunnel preferablyis established between a first virtual network interface in the firstnetwork entity and a second virtual network interface in the secondnetwork entity. Virtual network interfaces are known per se, wherein theuse of virtual network interfaces allows for simple routing in therespective network entities.

Preferably, data packets originating from different communicationservices are encapsulated in the same quick user datagram protocolinternet connection packet.

The method preferably comprises the steps of determining a maximumtransmission unit of at least one transmission path available fortransmitting data packets from the first network entity to the secondnetwork entity, and selecting the data size of the quick user datagramprotocol internet connection packets depending on the determined maximumtransmission unit.

Furthermore, the method preferably comprises the step of extractingcongestion control information from the data packets in the first and/orin the second network entity, wherein in particular said extractedcongestion control information is used for adapting a congestion controlof the quick user datagram protocol internet connection tunnel betweenthe first network entity and a second network entity.

According to another aspect, a network device is provided, whichcomprises at least two network interfaces, said network device beingadapted for multi-path communication using said at least two networkinterfaces, wherein the network device is further adapted forestablishing a quick user datagram protocol internet connection tunnelto a further network device, said further network device being adaptedfor multi-path communication, wherein the network device is adapted fortransmitting data packets to the further network device via said tunnel,said data packets being encapsulated within quick user datagram protocolinternet connection packets, wherein the quick user datagram protocolinternet connection packets are transmitted via multiple paths,extracting data packets from received quick user datagram protocolinternet connection packets, and for forwarding extracted data packetsto the respective destination.

The network device preferably is a hybrid customer premises equipmentrouter, a hybrid aggregation gateway or a mobile communication device.

In a further aspect, a communication system is provided, comprising atleast two network devices as described above, in particular acombination of a user equipment and a server of a communicationprovider.

While subject matter of the present disclosure has been illustrated anddescribed in detail in the drawings and foregoing description, suchillustration and description are to be considered illustrative orexemplary and not restrictive. Any statement made herein characterizingthe invention is also to be considered illustrative or exemplary and notrestrictive as the invention is defined by the claims. It will beunderstood that changes and modifications may be made, by those ofordinary skill in the art, within the scope of the following claims,which may include any combination of features from different embodimentsdescribed above.

The terms used in the claims should be construed to have the broadestreasonable interpretation consistent with the foregoing description. Forexample, the use of the article “a” or “the” in introducing an elementshould not be interpreted as being exclusive of a plurality of elements.Likewise, the recitation of “or” should be interpreted as beinginclusive, such that the recitation of “A or B” is not exclusive of “Aand B,” unless it is clear from the context or the foregoing descriptionthat only one of A and B is intended. Further, the recitation of “atleast one of A, B and C” should be interpreted as one or more of a groupof elements consisting of A, B and C, and should not be interpreted asrequiring at least one of each of the listed elements A, B and C,regardless of whether A, B and C are related as categories or otherwise.Moreover, the recitation of “A, B and/or C” or “at least one of A, B orC” should be interpreted as including any singular entity from thelisted elements, e.g., A, any subset from the listed elements, e.g., Aand B, or the entire list of elements A, B and C.

1. A method for transmitting data packets of at least one communicationservice from a first network entity to at least one destination networkentity, the method comprising: establishing a quick user datagramprotocol internet connection tunnel between the first network entity anda second network entity; transmitting the data packets from the firstnetwork entity to the second network entity via the quick user datagramprotocol internet connection tunnel, wherein the data packets areencapsulated within quick user datagram protocol internet connectionpackets, and wherein the quick user datagram protocol internetconnection packets are transmitted from the first network entity to thesecond network entity via multiple paths; extracting the data packetsfrom the received quick user datagram protocol internet connectionpackets in the second network entity; and forwarding the extracted datapackets from the second network entity to the a respective destinationnetwork entity.
 2. The method of claim 1, wherein information istransmitted from the first network entity to the second network entityindicating non-reliable transmission within the quick user datagramprotocol internet connection tunnel, and wherein the quick user datagramprotocol internet connection packets are transmitted non-reliably. 3.The method of claim 2, wherein the data packets and/or the quick userdatagram protocol internet connection packets comprise orderinginformation, and wherein forwarding the extracted data packets from thesecond network entity to the respective destination network entity isperformed in an order depending on the ordering information.
 4. Themethod of claim 3, wherein for forwarding, the received data packets arequeued in a reorder queue in the second network entity, wherein the datapackets in the reorder queue are reordered according to a pre-definedreorder criterion, and wherein data packets which are lost in thetransmission from the first network entity to the second network entityvia the tunnel are skipped in the reordering.
 5. The method of claim 1,wherein the quick user datagram protocol internet connection tunnel isestablished between a first virtual network interface in the firstnetwork entity and a second virtual network interface in the secondnetwork entity.
 6. The method of claim 1, wherein data packetsoriginating from different communication services are encapsulated inthe same quick user datagram protocol internet connection packet.
 7. Themethod of claim 1, further comprising: the steps of determining amaximum transmission unit of at least one transmission path availablefor transmitting data packets from the first network entity to thesecond network entity; and selecting the data size of the quick userdatagram protocol internet connection packets depending on thedetermined maximum transmission unit.
 8. The method of claim 1, furthercomprising: extracting congestion control information from the datapackets in the first network entity and/or in the second network entity,wherein the extracted congestion control information is used foradapting a congestion control of the quick user datagram protocolinternet connection tunnel between the first network entity and a secondnetwork entity.
 9. A network communication system, comprising: a firstnetwork device adapted for multi-path communication via at least twonetwork interfaces; and a second network device adapted for multi-pathcommunication; wherein the first network device is configured for:establishing a quick user datagram protocol internet connection tunnelto the second network device; and transmitting data packets to thesecond network device via the quick user datagram protocol internetconnection tunnel, wherein the data packets are encapsulated withinquick user datagram protocol internet connection packets, wherein thequick user datagram protocol internet connection packets are transmittedvia multiple paths; wherein the second network device is configured for:extracting the data packets from the received quick user datagramprotocol internet connection packets; and forwarding the extracted datapackets to a respective destination.
 10. The network communicationsystem of claim 9, wherein the first network device is a hybrid customerpremises equipment router, a hybrid aggregation gateway, or a mobilecommunication device.
 11. (canceled)
 12. One or more non-transitorycomputer-readable mediums having processor-executable instructionsstored thereon for transmitting data packets of at least onecommunication service from a first network entity to at least onedestination network entity, wherein the processor-executableinstructions, when executed, facilitate: establishing a quick userdatagram protocol internet connection tunnel between the first networkentity and a second network entity; transmitting the data packets fromthe first network entity to the second network entity via the quick userdatagram protocol internet connection tunnel, wherein the data packetsare encapsulated within quick user datagram protocol internet connectionpackets, and wherein the quick user datagram protocol internetconnection packets are transmitted from the first network entity to thesecond network entity via multiple paths; extracting the data packetsfrom the received quick user datagram protocol internet connectionpackets in the second network entity; and forwarding the extracted datapackets from the second network entity to a respective destinationnetwork entity.